A distributed antenna system (“DAS”) may extend the coverage of a telecommunications system by communicating signals between one or more base transceiver stations of a cellular communications network and one or more remote units. The remote units can wirelessly communicate with mobile devices located in the coverage area.
A remote unit can be limited to communicating signals having a maximum bandwidth. The maximum bandwidth for a remote unit can be based on physical characteristics of the antenna in the remote unit or the communicated signal. A typical bandwidth limitation for a remote unit is 75 MHz. In some circumstances, however, greater bandwidth is desirable for remote units.
One method for increasing the bandwidth available to remote units includes combining the bandwidth of different RF bands into a combined or composite RF band. The combined RF band can be created by overlapping a portion of two or more bands. One problem, however, associated with conventional methods for combining bands is that interference, group delay, and other ripple effects associated with overlapping the bands can negatively impact the communications performance of signals using the combined band. Ripple can include, for example, an amplitude, gain, or group delay variation, noise associated with summing noise of multiple signals, or local oscillator leakage that can arise when combining RF bands.
Accordingly, it is desirable to increase the bandwidth available to remote units in a wireless communication system, such as a DAS, without the negative ripple effects associated with combining multiple RF bands.